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configfs: fix race between dentry put and lookup
[linux-2.6.git] / net / ipv4 / ping.c
blob876c6ca2d8f9e77a28f1e629aa6523df1ee8f42f
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * "Ping" sockets
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 *
13 * Based on ipv4/udp.c code.
14 *
15 * Authors: Vasiliy Kulikov / Openwall (for Linux 2.6),
16 * Pavel Kankovsky (for Linux 2.4.32)
17 *
18 * Pavel gave all rights to bugs to Vasiliy,
19 * none of the bugs are Pavel's now.
20 *
21 */
22
23 #include <linux/uaccess.h>
24 #include <linux/types.h>
25 #include <linux/fcntl.h>
26 #include <linux/socket.h>
27 #include <linux/sockios.h>
28 #include <linux/in.h>
29 #include <linux/errno.h>
30 #include <linux/timer.h>
31 #include <linux/mm.h>
32 #include <linux/inet.h>
33 #include <linux/netdevice.h>
34 #include <net/snmp.h>
35 #include <net/ip.h>
36 #include <net/icmp.h>
37 #include <net/protocol.h>
38 #include <linux/skbuff.h>
39 #include <linux/proc_fs.h>
40 #include <linux/export.h>
41 #include <net/sock.h>
42 #include <net/ping.h>
43 #include <net/udp.h>
44 #include <net/route.h>
45 #include <net/inet_common.h>
46 #include <net/checksum.h>
47
48 #if IS_ENABLED(CONFIG_IPV6)
49 #include <linux/in6.h>
50 #include <linux/icmpv6.h>
51 #include <net/addrconf.h>
52 #include <net/ipv6.h>
53 #include <net/transp_v6.h>
54 #endif
55
56
57 struct ping_table ping_table;
58 struct pingv6_ops pingv6_ops;
59 EXPORT_SYMBOL_GPL(pingv6_ops);
60
61 static u16 ping_port_rover;
62
63 static inline int ping_hashfn(struct net *net, unsigned int num, unsigned int mask)
64 {
65 int res = (num + net_hash_mix(net)) & mask;
66
67 pr_debug("hash(%d) = %d\n", num, res);
68 return res;
69 }
70 EXPORT_SYMBOL_GPL(ping_hash);
71
72 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
73 struct net *net, unsigned int num)
74 {
75 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
76 }
77
78 int ping_get_port(struct sock *sk, unsigned short ident)
79 {
80 struct hlist_nulls_node *node;
81 struct hlist_nulls_head *hlist;
82 struct inet_sock *isk, *isk2;
83 struct sock *sk2 = NULL;
84
85 isk = inet_sk(sk);
86 write_lock_bh(&ping_table.lock);
87 if (ident == 0) {
88 u32 i;
89 u16 result = ping_port_rover + 1;
90
91 for (i = 0; i < (1L << 16); i++, result++) {
92 if (!result)
93 result++; /* avoid zero */
94 hlist = ping_hashslot(&ping_table, sock_net(sk),
95 result);
96 ping_portaddr_for_each_entry(sk2, node, hlist) {
97 isk2 = inet_sk(sk2);
98
99 if (isk2->inet_num == result)
100 goto next_port;
101 }
102
103 /* found */
104 ping_port_rover = ident = result;
105 break;
106 next_port:
107 ;
108 }
109 if (i >= (1L << 16))
110 goto fail;
111 } else {
112 hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
113 ping_portaddr_for_each_entry(sk2, node, hlist) {
114 isk2 = inet_sk(sk2);
115
116 /* BUG? Why is this reuse and not reuseaddr? ping.c
117 * doesn't turn off SO_REUSEADDR, and it doesn't expect
118 * that other ping processes can steal its packets.
119 */
120 if ((isk2->inet_num == ident) &&
121 (sk2 != sk) &&
122 (!sk2->sk_reuse || !sk->sk_reuse))
123 goto fail;
124 }
125 }
126
127 pr_debug("found port/ident = %d\n", ident);
128 isk->inet_num = ident;
129 if (sk_unhashed(sk)) {
130 pr_debug("was not hashed\n");
131 sock_hold(sk);
132 hlist_nulls_add_head(&sk->sk_nulls_node, hlist);
133 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
134 }
135 write_unlock_bh(&ping_table.lock);
136 return 0;
137
138 fail:
139 write_unlock_bh(&ping_table.lock);
140 return 1;
141 }
142 EXPORT_SYMBOL_GPL(ping_get_port);
143
144 void ping_hash(struct sock *sk)
145 {
146 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
147 BUG(); /* "Please do not press this button again." */
148 }
149
150 void ping_unhash(struct sock *sk)
151 {
152 struct inet_sock *isk = inet_sk(sk);
153 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
154 if (sk_hashed(sk)) {
155 write_lock_bh(&ping_table.lock);
156 hlist_nulls_del(&sk->sk_nulls_node);
157 sock_put(sk);
158 isk->inet_num = 0;
159 isk->inet_sport = 0;
160 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
161 write_unlock_bh(&ping_table.lock);
162 }
163 }
164 EXPORT_SYMBOL_GPL(ping_unhash);
165
166 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
167 {
168 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
169 struct sock *sk = NULL;
170 struct inet_sock *isk;
171 struct hlist_nulls_node *hnode;
172 int dif = skb->dev->ifindex;
173
174 if (skb->protocol == htons(ETH_P_IP)) {
175 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
176 (int)ident, &ip_hdr(skb)->daddr, dif);
177 #if IS_ENABLED(CONFIG_IPV6)
178 } else if (skb->protocol == htons(ETH_P_IPV6)) {
179 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
180 (int)ident, &ipv6_hdr(skb)->daddr, dif);
181 #endif
182 }
183
184 read_lock_bh(&ping_table.lock);
185
186 ping_portaddr_for_each_entry(sk, hnode, hslot) {
187 isk = inet_sk(sk);
188
189 pr_debug("iterate\n");
190 if (isk->inet_num != ident)
191 continue;
192
193 if (skb->protocol == htons(ETH_P_IP) &&
194 sk->sk_family == AF_INET) {
195 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
196 (int) isk->inet_num, &isk->inet_rcv_saddr,
197 sk->sk_bound_dev_if);
198
199 if (isk->inet_rcv_saddr &&
200 isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
201 continue;
202 #if IS_ENABLED(CONFIG_IPV6)
203 } else if (skb->protocol == htons(ETH_P_IPV6) &&
204 sk->sk_family == AF_INET6) {
205
206 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
207 (int) isk->inet_num,
208 &sk->sk_v6_rcv_saddr,
209 sk->sk_bound_dev_if);
210
211 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
212 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
213 &ipv6_hdr(skb)->daddr))
214 continue;
215 #endif
216 }
217
218 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
219 continue;
220
221 sock_hold(sk);
222 goto exit;
223 }
224
225 sk = NULL;
226 exit:
227 read_unlock_bh(&ping_table.lock);
228
229 return sk;
230 }
231
232 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
233 kgid_t *high)
234 {
235 kgid_t *data = net->ipv4.sysctl_ping_group_range;
236 unsigned int seq;
237
238 do {
239 seq = read_seqbegin(&net->ipv4.sysctl_local_ports.lock);
240
241 *low = data[0];
242 *high = data[1];
243 } while (read_seqretry(&net->ipv4.sysctl_local_ports.lock, seq));
244 }
245
246
247 int ping_init_sock(struct sock *sk)
248 {
249 struct net *net = sock_net(sk);
250 kgid_t group = current_egid();
251 struct group_info *group_info = get_current_groups();
252 int i, j, count = group_info->ngroups;
253 kgid_t low, high;
254
255 inet_get_ping_group_range_net(net, &low, &high);
256 if (gid_lte(low, group) && gid_lte(group, high))
257 return 0;
258
259 for (i = 0; i < group_info->nblocks; i++) {
260 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
261 for (j = 0; j < cp_count; j++) {
262 kgid_t gid = group_info->blocks[i][j];
263 if (gid_lte(low, gid) && gid_lte(gid, high))
264 return 0;
265 }
266
267 count -= cp_count;
268 }
269
270 return -EACCES;
271 }
272 EXPORT_SYMBOL_GPL(ping_init_sock);
273
274 void ping_close(struct sock *sk, long timeout)
275 {
276 pr_debug("ping_close(sk=%p,sk->num=%u)\n",
277 inet_sk(sk), inet_sk(sk)->inet_num);
278 pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
279
280 sk_common_release(sk);
281 }
282 EXPORT_SYMBOL_GPL(ping_close);
283
284 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
285 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
286 struct sockaddr *uaddr, int addr_len) {
287 struct net *net = sock_net(sk);
288 if (sk->sk_family == AF_INET) {
289 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
290 int chk_addr_ret;
291
292 if (addr_len < sizeof(*addr))
293 return -EINVAL;
294
295 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
296 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
297
298 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
299
300 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
301 chk_addr_ret = RTN_LOCAL;
302
303 if ((sysctl_ip_nonlocal_bind == 0 &&
304 isk->freebind == 0 && isk->transparent == 0 &&
305 chk_addr_ret != RTN_LOCAL) ||
306 chk_addr_ret == RTN_MULTICAST ||
307 chk_addr_ret == RTN_BROADCAST)
308 return -EADDRNOTAVAIL;
309
310 #if IS_ENABLED(CONFIG_IPV6)
311 } else if (sk->sk_family == AF_INET6) {
312 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
313 int addr_type, scoped, has_addr;
314 struct net_device *dev = NULL;
315
316 if (addr_len < sizeof(*addr))
317 return -EINVAL;
318
319 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
320 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
321
322 addr_type = ipv6_addr_type(&addr->sin6_addr);
323 scoped = __ipv6_addr_needs_scope_id(addr_type);
324 if ((addr_type != IPV6_ADDR_ANY &&
325 !(addr_type & IPV6_ADDR_UNICAST)) ||
326 (scoped && !addr->sin6_scope_id))
327 return -EINVAL;
328
329 rcu_read_lock();
330 if (addr->sin6_scope_id) {
331 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
332 if (!dev) {
333 rcu_read_unlock();
334 return -ENODEV;
335 }
336 }
337 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
338 scoped);
339 rcu_read_unlock();
340
341 if (!(isk->freebind || isk->transparent || has_addr ||
342 addr_type == IPV6_ADDR_ANY))
343 return -EADDRNOTAVAIL;
344
345 if (scoped)
346 sk->sk_bound_dev_if = addr->sin6_scope_id;
347 #endif
348 } else {
349 return -EAFNOSUPPORT;
350 }
351 return 0;
352 }
353
354 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
355 {
356 if (saddr->sa_family == AF_INET) {
357 struct inet_sock *isk = inet_sk(sk);
358 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
359 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
360 #if IS_ENABLED(CONFIG_IPV6)
361 } else if (saddr->sa_family == AF_INET6) {
362 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
363 struct ipv6_pinfo *np = inet6_sk(sk);
364 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
365 #endif
366 }
367 }
368
369 static void ping_clear_saddr(struct sock *sk, int dif)
370 {
371 sk->sk_bound_dev_if = dif;
372 if (sk->sk_family == AF_INET) {
373 struct inet_sock *isk = inet_sk(sk);
374 isk->inet_rcv_saddr = isk->inet_saddr = 0;
375 #if IS_ENABLED(CONFIG_IPV6)
376 } else if (sk->sk_family == AF_INET6) {
377 struct ipv6_pinfo *np = inet6_sk(sk);
378 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
379 memset(&np->saddr, 0, sizeof(np->saddr));
380 #endif
381 }
382 }
383 /*
384 * We need our own bind because there are no privileged id's == local ports.
385 * Moreover, we don't allow binding to multi- and broadcast addresses.
386 */
387
388 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
389 {
390 struct inet_sock *isk = inet_sk(sk);
391 unsigned short snum;
392 int err;
393 int dif = sk->sk_bound_dev_if;
394
395 err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
396 if (err)
397 return err;
398
399 lock_sock(sk);
400
401 err = -EINVAL;
402 if (isk->inet_num != 0)
403 goto out;
404
405 err = -EADDRINUSE;
406 ping_set_saddr(sk, uaddr);
407 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
408 if (ping_get_port(sk, snum) != 0) {
409 ping_clear_saddr(sk, dif);
410 goto out;
411 }
412
413 pr_debug("after bind(): num = %d, dif = %d\n",
414 (int)isk->inet_num,
415 (int)sk->sk_bound_dev_if);
416
417 err = 0;
418 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
419 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
420 #if IS_ENABLED(CONFIG_IPV6)
421 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
422 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
423 #endif
424
425 if (snum)
426 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
427 isk->inet_sport = htons(isk->inet_num);
428 isk->inet_daddr = 0;
429 isk->inet_dport = 0;
430
431 #if IS_ENABLED(CONFIG_IPV6)
432 if (sk->sk_family == AF_INET6)
433 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
434 #endif
435
436 sk_dst_reset(sk);
437 out:
438 release_sock(sk);
439 pr_debug("ping_v4_bind -> %d\n", err);
440 return err;
441 }
442 EXPORT_SYMBOL_GPL(ping_bind);
443
444 /*
445 * Is this a supported type of ICMP message?
446 */
447
448 static inline int ping_supported(int family, int type, int code)
449 {
450 return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
451 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
452 }
453
454 /*
455 * This routine is called by the ICMP module when it gets some
456 * sort of error condition.
457 */
458
459 void ping_err(struct sk_buff *skb, int offset, u32 info)
460 {
461 int family;
462 struct icmphdr *icmph;
463 struct inet_sock *inet_sock;
464 int type;
465 int code;
466 struct net *net = dev_net(skb->dev);
467 struct sock *sk;
468 int harderr;
469 int err;
470
471 if (skb->protocol == htons(ETH_P_IP)) {
472 family = AF_INET;
473 type = icmp_hdr(skb)->type;
474 code = icmp_hdr(skb)->code;
475 icmph = (struct icmphdr *)(skb->data + offset);
476 } else if (skb->protocol == htons(ETH_P_IPV6)) {
477 family = AF_INET6;
478 type = icmp6_hdr(skb)->icmp6_type;
479 code = icmp6_hdr(skb)->icmp6_code;
480 icmph = (struct icmphdr *) (skb->data + offset);
481 } else {
482 BUG();
483 }
484
485 /* We assume the packet has already been checked by icmp_unreach */
486
487 if (!ping_supported(family, icmph->type, icmph->code))
488 return;
489
490 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
491 skb->protocol, type, code, ntohs(icmph->un.echo.id),
492 ntohs(icmph->un.echo.sequence));
493
494 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
495 if (sk == NULL) {
496 pr_debug("no socket, dropping\n");
497 return; /* No socket for error */
498 }
499 pr_debug("err on socket %p\n", sk);
500
501 err = 0;
502 harderr = 0;
503 inet_sock = inet_sk(sk);
504
505 if (skb->protocol == htons(ETH_P_IP)) {
506 switch (type) {
507 default:
508 case ICMP_TIME_EXCEEDED:
509 err = EHOSTUNREACH;
510 break;
511 case ICMP_SOURCE_QUENCH:
512 /* This is not a real error but ping wants to see it.
513 * Report it with some fake errno.
514 */
515 err = EREMOTEIO;
516 break;
517 case ICMP_PARAMETERPROB:
518 err = EPROTO;
519 harderr = 1;
520 break;
521 case ICMP_DEST_UNREACH:
522 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
523 ipv4_sk_update_pmtu(skb, sk, info);
524 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
525 err = EMSGSIZE;
526 harderr = 1;
527 break;
528 }
529 goto out;
530 }
531 err = EHOSTUNREACH;
532 if (code <= NR_ICMP_UNREACH) {
533 harderr = icmp_err_convert[code].fatal;
534 err = icmp_err_convert[code].errno;
535 }
536 break;
537 case ICMP_REDIRECT:
538 /* See ICMP_SOURCE_QUENCH */
539 ipv4_sk_redirect(skb, sk);
540 err = EREMOTEIO;
541 break;
542 }
543 #if IS_ENABLED(CONFIG_IPV6)
544 } else if (skb->protocol == htons(ETH_P_IPV6)) {
545 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
546 #endif
547 }
548
549 /*
550 * RFC1122: OK. Passes ICMP errors back to application, as per
551 * 4.1.3.3.
552 */
553 if ((family == AF_INET && !inet_sock->recverr) ||
554 (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
555 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
556 goto out;
557 } else {
558 if (family == AF_INET) {
559 ip_icmp_error(sk, skb, err, 0 /* no remote port */,
560 info, (u8 *)icmph);
561 #if IS_ENABLED(CONFIG_IPV6)
562 } else if (family == AF_INET6) {
563 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
564 info, (u8 *)icmph);
565 #endif
566 }
567 }
568 sk->sk_err = err;
569 sk->sk_error_report(sk);
570 out:
571 sock_put(sk);
572 }
573 EXPORT_SYMBOL_GPL(ping_err);
574
575 /*
576 * Copy and checksum an ICMP Echo packet from user space into a buffer
577 * starting from the payload.
578 */
579
580 int ping_getfrag(void *from, char *to,
581 int offset, int fraglen, int odd, struct sk_buff *skb)
582 {
583 struct pingfakehdr *pfh = (struct pingfakehdr *)from;
584
585 if (offset == 0) {
586 if (fraglen < sizeof(struct icmphdr))
587 BUG();
588 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr),
589 pfh->iov, 0, fraglen - sizeof(struct icmphdr),
590 &pfh->wcheck))
591 return -EFAULT;
592 } else if (offset < sizeof(struct icmphdr)) {
593 BUG();
594 } else {
595 if (csum_partial_copy_fromiovecend
596 (to, pfh->iov, offset - sizeof(struct icmphdr),
597 fraglen, &pfh->wcheck))
598 return -EFAULT;
599 }
600
601 #if IS_ENABLED(CONFIG_IPV6)
602 /* For IPv6, checksum each skb as we go along, as expected by
603 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
604 * wcheck, it will be finalized in ping_v4_push_pending_frames.
605 */
606 if (pfh->family == AF_INET6) {
607 skb->csum = pfh->wcheck;
608 skb->ip_summed = CHECKSUM_NONE;
609 pfh->wcheck = 0;
610 }
611 #endif
612
613 return 0;
614 }
615 EXPORT_SYMBOL_GPL(ping_getfrag);
616
617 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
618 struct flowi4 *fl4)
619 {
620 struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
621
622 pfh->wcheck = csum_partial((char *)&pfh->icmph,
623 sizeof(struct icmphdr), pfh->wcheck);
624 pfh->icmph.checksum = csum_fold(pfh->wcheck);
625 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
626 skb->ip_summed = CHECKSUM_NONE;
627 return ip_push_pending_frames(sk, fl4);
628 }
629
630 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
631 void *user_icmph, size_t icmph_len) {
632 u8 type, code;
633
634 if (len > 0xFFFF)
635 return -EMSGSIZE;
636
637 /*
638 * Check the flags.
639 */
640
641 /* Mirror BSD error message compatibility */
642 if (msg->msg_flags & MSG_OOB)
643 return -EOPNOTSUPP;
644
645 /*
646 * Fetch the ICMP header provided by the userland.
647 * iovec is modified! The ICMP header is consumed.
648 */
649 if (memcpy_fromiovec(user_icmph, msg->msg_iov, icmph_len))
650 return -EFAULT;
651
652 if (family == AF_INET) {
653 type = ((struct icmphdr *) user_icmph)->type;
654 code = ((struct icmphdr *) user_icmph)->code;
655 #if IS_ENABLED(CONFIG_IPV6)
656 } else if (family == AF_INET6) {
657 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
658 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
659 #endif
660 } else {
661 BUG();
662 }
663
664 if (!ping_supported(family, type, code))
665 return -EINVAL;
666
667 return 0;
668 }
669 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
670
671 int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
672 size_t len)
673 {
674 struct net *net = sock_net(sk);
675 struct flowi4 fl4;
676 struct inet_sock *inet = inet_sk(sk);
677 struct ipcm_cookie ipc;
678 struct icmphdr user_icmph;
679 struct pingfakehdr pfh;
680 struct rtable *rt = NULL;
681 struct ip_options_data opt_copy;
682 int free = 0;
683 __be32 saddr, daddr, faddr;
684 u8 tos;
685 int err;
686
687 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
688
689 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
690 sizeof(user_icmph));
691 if (err)
692 return err;
693
694 /*
695 * Get and verify the address.
696 */
697
698 if (msg->msg_name) {
699 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
700 if (msg->msg_namelen < sizeof(*usin))
701 return -EINVAL;
702 if (usin->sin_family != AF_INET)
703 return -EINVAL;
704 daddr = usin->sin_addr.s_addr;
705 /* no remote port */
706 } else {
707 if (sk->sk_state != TCP_ESTABLISHED)
708 return -EDESTADDRREQ;
709 daddr = inet->inet_daddr;
710 /* no remote port */
711 }
712
713 ipc.addr = inet->inet_saddr;
714 ipc.opt = NULL;
715 ipc.oif = sk->sk_bound_dev_if;
716 ipc.tx_flags = 0;
717 ipc.ttl = 0;
718 ipc.tos = -1;
719
720 sock_tx_timestamp(sk, &ipc.tx_flags);
721
722 if (msg->msg_controllen) {
723 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
724 if (err)
725 return err;
726 if (ipc.opt)
727 free = 1;
728 }
729 if (!ipc.opt) {
730 struct ip_options_rcu *inet_opt;
731
732 rcu_read_lock();
733 inet_opt = rcu_dereference(inet->inet_opt);
734 if (inet_opt) {
735 memcpy(&opt_copy, inet_opt,
736 sizeof(*inet_opt) + inet_opt->opt.optlen);
737 ipc.opt = &opt_copy.opt;
738 }
739 rcu_read_unlock();
740 }
741
742 saddr = ipc.addr;
743 ipc.addr = faddr = daddr;
744
745 if (ipc.opt && ipc.opt->opt.srr) {
746 if (!daddr)
747 return -EINVAL;
748 faddr = ipc.opt->opt.faddr;
749 }
750 tos = get_rttos(&ipc, inet);
751 if (sock_flag(sk, SOCK_LOCALROUTE) ||
752 (msg->msg_flags & MSG_DONTROUTE) ||
753 (ipc.opt && ipc.opt->opt.is_strictroute)) {
754 tos |= RTO_ONLINK;
755 }
756
757 if (ipv4_is_multicast(daddr)) {
758 if (!ipc.oif)
759 ipc.oif = inet->mc_index;
760 if (!saddr)
761 saddr = inet->mc_addr;
762 } else if (!ipc.oif)
763 ipc.oif = inet->uc_index;
764
765 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
766 RT_SCOPE_UNIVERSE, sk->sk_protocol,
767 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
768
769 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
770 rt = ip_route_output_flow(net, &fl4, sk);
771 if (IS_ERR(rt)) {
772 err = PTR_ERR(rt);
773 rt = NULL;
774 if (err == -ENETUNREACH)
775 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
776 goto out;
777 }
778
779 err = -EACCES;
780 if ((rt->rt_flags & RTCF_BROADCAST) &&
781 !sock_flag(sk, SOCK_BROADCAST))
782 goto out;
783
784 if (msg->msg_flags & MSG_CONFIRM)
785 goto do_confirm;
786 back_from_confirm:
787
788 if (!ipc.addr)
789 ipc.addr = fl4.daddr;
790
791 lock_sock(sk);
792
793 pfh.icmph.type = user_icmph.type; /* already checked */
794 pfh.icmph.code = user_icmph.code; /* ditto */
795 pfh.icmph.checksum = 0;
796 pfh.icmph.un.echo.id = inet->inet_sport;
797 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
798 pfh.iov = msg->msg_iov;
799 pfh.wcheck = 0;
800 pfh.family = AF_INET;
801
802 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
803 0, &ipc, &rt, msg->msg_flags);
804 if (err)
805 ip_flush_pending_frames(sk);
806 else
807 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
808 release_sock(sk);
809
810 out:
811 ip_rt_put(rt);
812 if (free)
813 kfree(ipc.opt);
814 if (!err) {
815 icmp_out_count(sock_net(sk), user_icmph.type);
816 return len;
817 }
818 return err;
819
820 do_confirm:
821 dst_confirm(&rt->dst);
822 if (!(msg->msg_flags & MSG_PROBE) || len)
823 goto back_from_confirm;
824 err = 0;
825 goto out;
826 }
827
828 int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
829 size_t len, int noblock, int flags, int *addr_len)
830 {
831 struct inet_sock *isk = inet_sk(sk);
832 int family = sk->sk_family;
833 struct sk_buff *skb;
834 int copied, err;
835
836 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
837
838 err = -EOPNOTSUPP;
839 if (flags & MSG_OOB)
840 goto out;
841
842 if (flags & MSG_ERRQUEUE) {
843 if (family == AF_INET) {
844 return ip_recv_error(sk, msg, len);
845 #if IS_ENABLED(CONFIG_IPV6)
846 } else if (family == AF_INET6) {
847 return pingv6_ops.ipv6_recv_error(sk, msg, len);
848 #endif
849 }
850 }
851
852 skb = skb_recv_datagram(sk, flags, noblock, &err);
853 if (!skb)
854 goto out;
855
856 copied = skb->len;
857 if (copied > len) {
858 msg->msg_flags |= MSG_TRUNC;
859 copied = len;
860 }
861
862 /* Don't bother checking the checksum */
863 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
864 if (err)
865 goto done;
866
867 sock_recv_timestamp(msg, sk, skb);
868
869 /* Copy the address and add cmsg data. */
870 if (family == AF_INET) {
871 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
872
873 if (sin) {
874 sin->sin_family = AF_INET;
875 sin->sin_port = 0 /* skb->h.uh->source */;
876 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
877 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
878 *addr_len = sizeof(*sin);
879 }
880
881 if (isk->cmsg_flags)
882 ip_cmsg_recv(msg, skb);
883
884 #if IS_ENABLED(CONFIG_IPV6)
885 } else if (family == AF_INET6) {
886 struct ipv6_pinfo *np = inet6_sk(sk);
887 struct ipv6hdr *ip6 = ipv6_hdr(skb);
888 struct sockaddr_in6 *sin6 =
889 (struct sockaddr_in6 *)msg->msg_name;
890
891 if (sin6) {
892 sin6->sin6_family = AF_INET6;
893 sin6->sin6_port = 0;
894 sin6->sin6_addr = ip6->saddr;
895 sin6->sin6_flowinfo = 0;
896 if (np->sndflow)
897 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
898 sin6->sin6_scope_id =
899 ipv6_iface_scope_id(&sin6->sin6_addr,
900 IP6CB(skb)->iif);
901 *addr_len = sizeof(*sin6);
902 }
903
904 if (inet6_sk(sk)->rxopt.all)
905 pingv6_ops.ip6_datagram_recv_ctl(sk, msg, skb);
906 #endif
907 } else {
908 BUG();
909 }
910
911 err = copied;
912
913 done:
914 skb_free_datagram(sk, skb);
915 out:
916 pr_debug("ping_recvmsg -> %d\n", err);
917 return err;
918 }
919 EXPORT_SYMBOL_GPL(ping_recvmsg);
920
921 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
922 {
923 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
924 inet_sk(sk), inet_sk(sk)->inet_num, skb);
925 if (sock_queue_rcv_skb(sk, skb) < 0) {
926 kfree_skb(skb);
927 pr_debug("ping_queue_rcv_skb -> failed\n");
928 return -1;
929 }
930 return 0;
931 }
932 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
933
934
935 /*
936 * All we need to do is get the socket.
937 */
938
939 void ping_rcv(struct sk_buff *skb)
940 {
941 struct sock *sk;
942 struct net *net = dev_net(skb->dev);
943 struct icmphdr *icmph = icmp_hdr(skb);
944
945 /* We assume the packet has already been checked by icmp_rcv */
946
947 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
948 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
949
950 /* Push ICMP header back */
951 skb_push(skb, skb->data - (u8 *)icmph);
952
953 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
954 if (sk != NULL) {
955 pr_debug("rcv on socket %p\n", sk);
956 ping_queue_rcv_skb(sk, skb_get(skb));
957 sock_put(sk);
958 return;
959 }
960 pr_debug("no socket, dropping\n");
961
962 /* We're called from icmp_rcv(). kfree_skb() is done there. */
963 }
964 EXPORT_SYMBOL_GPL(ping_rcv);
965
966 struct proto ping_prot = {
967 .name = "PING",
968 .owner = THIS_MODULE,
969 .init = ping_init_sock,
970 .close = ping_close,
971 .connect = ip4_datagram_connect,
972 .disconnect = udp_disconnect,
973 .setsockopt = ip_setsockopt,
974 .getsockopt = ip_getsockopt,
975 .sendmsg = ping_v4_sendmsg,
976 .recvmsg = ping_recvmsg,
977 .bind = ping_bind,
978 .backlog_rcv = ping_queue_rcv_skb,
979 .release_cb = ip4_datagram_release_cb,
980 .hash = ping_hash,
981 .unhash = ping_unhash,
982 .get_port = ping_get_port,
983 .obj_size = sizeof(struct inet_sock),
984 };
985 EXPORT_SYMBOL(ping_prot);
986
987 #ifdef CONFIG_PROC_FS
988
989 static struct sock *ping_get_first(struct seq_file *seq, int start)
990 {
991 struct sock *sk;
992 struct ping_iter_state *state = seq->private;
993 struct net *net = seq_file_net(seq);
994
995 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
996 ++state->bucket) {
997 struct hlist_nulls_node *node;
998 struct hlist_nulls_head *hslot;
999
1000 hslot = &ping_table.hash[state->bucket];
1001
1002 if (hlist_nulls_empty(hslot))
1003 continue;
1004
1005 sk_nulls_for_each(sk, node, hslot) {
1006 if (net_eq(sock_net(sk), net) &&
1007 sk->sk_family == state->family)
1008 goto found;
1009 }
1010 }
1011 sk = NULL;
1012 found:
1013 return sk;
1014 }
1015
1016 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1017 {
1018 struct ping_iter_state *state = seq->private;
1019 struct net *net = seq_file_net(seq);
1020
1021 do {
1022 sk = sk_nulls_next(sk);
1023 } while (sk && (!net_eq(sock_net(sk), net)));
1024
1025 if (!sk)
1026 return ping_get_first(seq, state->bucket + 1);
1027 return sk;
1028 }
1029
1030 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1031 {
1032 struct sock *sk = ping_get_first(seq, 0);
1033
1034 if (sk)
1035 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1036 --pos;
1037 return pos ? NULL : sk;
1038 }
1039
1040 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1041 {
1042 struct ping_iter_state *state = seq->private;
1043 state->bucket = 0;
1044 state->family = family;
1045
1046 read_lock_bh(&ping_table.lock);
1047
1048 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1049 }
1050 EXPORT_SYMBOL_GPL(ping_seq_start);
1051
1052 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1053 {
1054 return ping_seq_start(seq, pos, AF_INET);
1055 }
1056
1057 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1058 {
1059 struct sock *sk;
1060
1061 if (v == SEQ_START_TOKEN)
1062 sk = ping_get_idx(seq, 0);
1063 else
1064 sk = ping_get_next(seq, v);
1065
1066 ++*pos;
1067 return sk;
1068 }
1069 EXPORT_SYMBOL_GPL(ping_seq_next);
1070
1071 void ping_seq_stop(struct seq_file *seq, void *v)
1072 {
1073 read_unlock_bh(&ping_table.lock);
1074 }
1075 EXPORT_SYMBOL_GPL(ping_seq_stop);
1076
1077 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1078 int bucket)
1079 {
1080 struct inet_sock *inet = inet_sk(sp);
1081 __be32 dest = inet->inet_daddr;
1082 __be32 src = inet->inet_rcv_saddr;
1083 __u16 destp = ntohs(inet->inet_dport);
1084 __u16 srcp = ntohs(inet->inet_sport);
1085
1086 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1087 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1088 bucket, src, srcp, dest, destp, sp->sk_state,
1089 sk_wmem_alloc_get(sp),
1090 sk_rmem_alloc_get(sp),
1091 0, 0L, 0,
1092 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1093 0, sock_i_ino(sp),
1094 atomic_read(&sp->sk_refcnt), sp,
1095 atomic_read(&sp->sk_drops));
1096 }
1097
1098 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1099 {
1100 seq_setwidth(seq, 127);
1101 if (v == SEQ_START_TOKEN)
1102 seq_puts(seq, " sl local_address rem_address st tx_queue "
1103 "rx_queue tr tm->when retrnsmt uid timeout "
1104 "inode ref pointer drops");
1105 else {
1106 struct ping_iter_state *state = seq->private;
1107
1108 ping_v4_format_sock(v, seq, state->bucket);
1109 }
1110 seq_pad(seq, '\n');
1111 return 0;
1112 }
1113
1114 static const struct seq_operations ping_v4_seq_ops = {
1115 .show = ping_v4_seq_show,
1116 .start = ping_v4_seq_start,
1117 .next = ping_seq_next,
1118 .stop = ping_seq_stop,
1119 };
1120
1121 static int ping_seq_open(struct inode *inode, struct file *file)
1122 {
1123 struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1124 return seq_open_net(inode, file, &afinfo->seq_ops,
1125 sizeof(struct ping_iter_state));
1126 }
1127
1128 const struct file_operations ping_seq_fops = {
1129 .open = ping_seq_open,
1130 .read = seq_read,
1131 .llseek = seq_lseek,
1132 .release = seq_release_net,
1133 };
1134 EXPORT_SYMBOL_GPL(ping_seq_fops);
1135
1136 static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1137 .name = "icmp",
1138 .family = AF_INET,
1139 .seq_fops = &ping_seq_fops,
1140 .seq_ops = {
1141 .start = ping_v4_seq_start,
1142 .show = ping_v4_seq_show,
1143 .next = ping_seq_next,
1144 .stop = ping_seq_stop,
1145 },
1146 };
1147
1148 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1149 {
1150 struct proc_dir_entry *p;
1151 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1152 afinfo->seq_fops, afinfo);
1153 if (!p)
1154 return -ENOMEM;
1155 return 0;
1156 }
1157 EXPORT_SYMBOL_GPL(ping_proc_register);
1158
1159 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1160 {
1161 remove_proc_entry(afinfo->name, net->proc_net);
1162 }
1163 EXPORT_SYMBOL_GPL(ping_proc_unregister);
1164
1165 static int __net_init ping_v4_proc_init_net(struct net *net)
1166 {
1167 return ping_proc_register(net, &ping_v4_seq_afinfo);
1168 }
1169
1170 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1171 {
1172 ping_proc_unregister(net, &ping_v4_seq_afinfo);
1173 }
1174
1175 static struct pernet_operations ping_v4_net_ops = {
1176 .init = ping_v4_proc_init_net,
1177 .exit = ping_v4_proc_exit_net,
1178 };
1179
1180 int __init ping_proc_init(void)
1181 {
1182 return register_pernet_subsys(&ping_v4_net_ops);
1183 }
1184
1185 void ping_proc_exit(void)
1186 {
1187 unregister_pernet_subsys(&ping_v4_net_ops);
1188 }
1189
1190 #endif
1191
1192 void __init ping_init(void)
1193 {
1194 int i;
1195
1196 for (i = 0; i < PING_HTABLE_SIZE; i++)
1197 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1198 rwlock_init(&ping_table.lock);
1199 }
Linus' kernel tree